Neptune's Moons

Neptune has at least 14 moons known to orbit it. Its largest moon is Triton which was discovered in 1846 by the English beer brewer and astronomer William Lassell. It was discovered only 17 days after Neptune itself was first observed. Triton is the only major moon of a planet to orbit in the opposite direction of the planet's rotation. This retrograde orbit suggests that Triton might not have originally formed around Neptune as most large moons do, but was captured by it instead.

Crescents of Neptune and Triton from Voyager 2 in 1989 (Image credit: NASA/JPL)

Voyager 2 is a spacecraft that visited Neptune in 1989. Prior to its arrival, the only moon other than Triton to be discovered in orbit of Neptune was Nereid by the Dutch astronomer Gerard Kuiper in 1949. Voyager 2 would find most of Neptune's known inner moons. Astronomers have since discovered a handful of other moons orbiting Neptune. These are mostly outer moons orbiting at great distances away from Neptune. Its most distant moon is Neso which is over 48 million kilometres (30 million miles) away from Neptune itself, making it the most distant moon of any planet in the solar system.

Neptune's moons can be split into four distinct groups as listed below. Following that is a list of the moons themselves.

Groups of Neptune's Moons

List of Neptune's Moons